Modulating electric valve



Feb. 4, 1936. L' 1 CUNNgNGHAM 2,029,465

MODULATING ELECTRIC VALVE Filed Nov. 11, 1953 2 Sheets-Sheet l 1m/vento@ I EWlS L. CUNNNGHAM @MWI-W atten/m11 Feb- 4, 1936 L. l.. CUNNINGHAM 2,029,465

MODULATING. ELECTRIC VALVE Filed Nov. ll, 1955 2 Sheets-Sheet 2 FIG. 2

" IOI S14/vento@ LEWIS L .CUNNINGHAM @aI/@WWW Patented Feb. 4, 1936 UNITED STATES P'TT OFFICE l signor to Minneapolis-Honeywell Regulator Company, Minneapolis, Minn., a corporation of Delaware Application November il, 1933, Serial No. 697,686 29 claims. (oi. 23e-74) The present invention relates to the positioning of an element or a mechanism in accordance with the'changes in a condition or the movements 4of a movable member and is specically directed b to the control of a valve by which the ow of fuel,

such as gas, to a burner is controlled.

One of the objects of the invention is the provision of a fully electrical system of control of simple arrangement which does not require comm plicated mechanical latching or other similar mechanisms.

Another object of the invention is the provision of an electrical control system for an element to be controlled vby which the element is initially ,5 given a rapid quick movement to a predetermined position and is thereafter-slowly moved as the result of movements of a movable member or the changes in a condition. More specically, the motive means for the element to be controlled is o operatively deenergized until conditions are such as to require a substantial movement of the element at which time the motive means is energized in such manner as to supply the necessary movement to the element. The element is thereafter maintained in its new position by energizing the motive means toa different extent but without the aid of mechanical latching mechanisms.

A further object of the invention is the provision 30 of a control device in which an element to be controlled is normally biased to one of its extreme positions, is moved against its bias to another of its positions by completely energizing a rotary electrical motor and is thereafter maintained in its new position by only partially energizing the motor. L

Another object of the invention is the provision of an electrical control system for a valve whereby the valve is given a quick initial movement I o from closed position to an appreciable open position and is thereafter modulated in accordance with demands until the valve approaches nearly closed position whereupon it is quickly moved to closed position. .g3 A further object of the invention is the provision of a variable flow controlling mechanism which remains in its flow obstructing position until there is a demand for an appreciable ow whereupon the mechanism is operated initially to y establish a flow which is considerably larger than the demand and is automatically returned to a position permitting the desired ow, after which the ow is modulated in accordance with demands. When the ow demand decreases to a predetermined minimum, the mechanism of the present invention thereupon ceases modulating the :dow and again moves the ilow controllingr mechanism to ow obstructing position.

Another object of the invention is the provision of an electrically controlled valve which, upon an initial relatively small demand, opens widely and then returns to a position corresponding to the demand and thereafter modulates in accordance with the demands.'

Other objects of the invention will be found in the following detailed description and accompanying drawings and the appended claims.

In the drawings,

Fig. 1 is a side view of a valve mechanism built in accordance with ythe present invention, certain parts being in section and others being broken away to show the details of construction more clearly,

Fig. 2 is a diagrammatic showing of the control system by means of which the valve is controlled, and

Fig. 3 is a partial View showing a modified form of the invention.

Referring iirst to Fig. 1 of the drawings, the invention is herein shown as applied to a gas valve comprising a casing I II having outlet and inlet openings II and I2 respectively formed therein and a partition wall I3 which divides the valve casing I0 into inlet and outlet chambers. The partition I3 is provided with a valve opening I4 which forms a valve seat I5. An inverted screw I6, having an enlarged head, receives an adjustable flow throttling assembly I1, a washer I8, a valve disc I9, and a valve disc retainer 20, in the order named. A nut 2| clamps these parts against the head of screw I6 so that the screw IB, throttling assembly I1, washer I8, disc I9 and disc retainer 20 form a unitary assembly. The valve disc 20 cooperates with valve seat I5 to prevent or permit the ilow of fluid through the valve.

The throttling assembly I'I comprises a cylindrical member 22 which is provided with openings 23 and a disc 24 which is provided with downwardly extending skirts 25. Each skirt 25 is provided with an inwardly extending radial projection 26. The lower portion of valve casing I0 is provided with a threaded opening which receives a bonnet 2I through which passes a pin 28 having an operating head 29. That end of pin 28 which terminates Within valve casing I0 receives cross bar 3U. A coiled spring 3|, which is conned between bonnet 21 and operating head 29, biases pin 28 and cross bar 30 to the' position YShown in Fig. 1. A cap 32 which is threaded into Vbonnet 21 and encloses pin 28 -and coiled spring 3| prevents the passage of gas from inside the casing I0, through the opening in bonnet 21 through which pin 28 passes, and to the atmosphere.

The skirts 25 are adapted to cover more or less of the openings 23 in order to increase or decrease the width. of these openings whereby upon upprojections 26 and rotates skirts 25 within the cylindrical member 22. In `this manner, lthe maximum ow of gas through'openings' 23 on upward movement of screw I6 may be adjusted.

The valve casing I8 is also provided with a. vertical cylindrical extension 33 which is provided with exterior screw threads which receive a nut `34 that clamps a disc 35 vagainst the end of extension 33.` Riveted to disc 35 is a cup-shaped member 36 which is secured to a circular base plate 31 by means of suitable screws and nuts 38A, there being a sealing-oil diaphragm 39A clamped between cup-shaped member 36 and base plate 31.

Base plate 31 supports a pair ofvertical extending frame plates 38 and 39.

A valve stem 40 is loosely received'l within and pivotedto the upper end of screw I6 and extends upwardly through disc 35, cup-shaped member 36, diaphragm 39A, andan opening 4| in base plate 31 and terminates above base plate 31 and between frame plates 38 and 39. The upper end of fvalve stem 46 is threaded as indicated at 42. Clamping members 43 are placed on each side of diaphragm 39A and clamped there-against by means of nuts 44 which cooperate with the threaded portion 42 of valve stem 40.* In this manner, valve stem 40 is free to move vertically but the sealing-olf diaphragm 39A prevents the escape of gas from cup member 36 to the atmosphere. A coiled spring 45 is confined between disc 35 and a spring retainer 46 which rests upon the upper end of screw I6 whereby the coiled spring 45 acts to bias the valve disc I9 and throttling assembly |1 to the position shown in the drawings wherein no gas is permitted to ilow through the valve casing I8.

' A lever 41 is located between frame plates 38 and 39 and is pivoted upon a pin 48 which is supported in these base plates. 49 is pivoted to lever 41 as indicated at 50. Valve stem 40 extends within U-shaped bracket 49 and is provided with a nut 5| whereby upward movement of U-shaped bracket 49 serves to lift valve stern 4I).l A pin 52 is secured to lever 41 near the left hand end thereof and pivotally supports an upwardly extending link 53 which is provided with a hook 54. A large gear 551s secured to a shaft 56 which is journalled in frameplates 38 and 39. Gear 55 is provideduwith a crank pin 51 which is adapted', upon clockwise rotation of gear 55, to engage the hook 54 of link 53 and raisethe link 53. Such upward movement' of link 53 rotates lever 41 in a clockwise direction about pin 48 whereby valve stem 48 is elevated. The upper end of link 53 is biased into engagement'with the hub 58 of a gear 55 by meansiof a spring 59 which engages the left side of link 53, passes around pin 52 and a second pin 68 secured to lever 41, and is Y then hooked over the left hand end of lever 41.

A U-shaped bracket` position wherein its crank pin 51. I

Gear 55 meshes with a pinion 6| which is formed integral with a gear 62. Gear 62 and pinion 6| are journalled onf a shaft 63v mounted in hook 54 is ready Ito receive frame plates 38 and 39. rGear 62 in turn meshes with a pinion 64 whichis formed integral with a gear 65 journalled on a shaft 66 that is likewise mounted in frame plates 38 and 39. .All of -these gears and pinios are located between frame plates 38 and 38. Gear 65 meshes with a rotor pinion 61 which is secured upon a rotor shaft 68 that extends rearwardly through frame .plate 38. Rotor shaft'68 carries the rotor 69 of an induction motor 10 which is located `in backr of frame plate 38. It will be `understood that the motor 10 in actual construction is located directly in back of plate 38 and that it has been shown as extending beyond plate 38- merely for clarity of illustration. The induction motor 10 is provided with-a :tield core 1| having four poles 12 all of which are split into two portions and one of these portions vof each of the eld poles is providedwithv the usual copper shading ring- 13. One .of poles, 12 is providedv with a eld winding 14 and the oppositely disposed pole 12 is `provitled with a similar eld winding 15, there being no Vield windings on the other two poles in 'this particular type of motor.

On -energization of eld windings 14 and 15,

rotor 69 is rotated in. a clockwise vdirection and Aslowly drives gear 55 in a clockwise direction through the above described speed reducing and torque multiplying gear train. The initial clockvWise rotation of gear 55 serves to take up the lost motion between crank pin 51 and hook 54. Further clockwise rotation of gear 55 serves'to lift hook 54 by means of crank pin 51 whereby valve stem.40 is elevated. Upon deenergization of both eld windings 14 and 15, the coiled spring 45 returns the valve disc I9 into engagement with i Valve seat I5 and the various gears and pinions.

and motor rotor are rotated in the reverse directions. When the valve has completely seated the gears and motor rotor ,may continue rotating until all of theirenergy is expended and they will thereupon substantially assume' the position shown in Fig. 1 of the drawings.

be manually latched in such position as to maintain the valve in a partial open position. Such.

operation of pin 16 closes recycling switches 11 and 18 in the usual manner.

A panel of insulating material is supported 1 ing insulated from core 83 in any suitable manner. The brackets 8| and 82 also support a guide pin 81. An actuating assembly comprises a slider 88, which is adapted to slide up and down upon guide pin 81, and a strip of insulating material 89 which is received in a vertical slot 90 formed in a bracket l9| which is carried by panel 88. A limit switch assembly comprises a contact post 92 and a flexible contact arm A93 which are adjustably secured on the rear surface of panel 80 by means of a screw 94 and extendthrough a slot 95 formed in insulating panel 80. The contact post 92 and ilexible contact arm 93 are nor- `'lheapparatus is provided with the usual man- `ually operable pin 16 by which the lever 41 may mally in engagement but upon extreme upward movement of slider 88, strip 39 passes over contact post 92 and engages flexible contact arm 93 to raise the same out of engagement with contact post 92. A similar limit switch assembly comprises a contact post 9B and a flexible contact arm 91 which are adjustably secured to the rear face of insulating panel Si) by means of a screw 93. Contact post 98 and exible contact arm 31 also extend forwardly through slot 95 and are normally in engagement. the slider 88 in its lowermost position as shown in the drawings, strip 89 has passed over contact post 93 and engaged ilexible contact arm 91 to move the `same downwardly out of engagement with contact post 96. Slider 88 is normally biased to its lowermost position by means of a coled spring S9 which surrounds guide pin 81 and a cap |00, which is mounted on guide pin 81, limits the upward movement of slider 38. The slider 88 supports a flexible contact linger I| which is adapted to engage the resistance 8,4 upon upward movement of slider 88. However, a bracket |02 which is adjustably secured to panel 80 is provided with a cam surface |03 upon which flexible finger IOI is adapted to ride during upward movement of slider 88 whereby the flexible contact `finger |0| is raised from engagement with resistance 84 during part of the travel of slider 88. an extension in the form of a contact finger |05 which engages the rear surface of resistance 84 and may be adjusted therealong. The shaft 56 extends forwardly through` panel 80 and carries an actuator |06 of insulating material.

Upon clockwise rotation of gear 55 actuator |06 i approaches the extended end of slider 88 and crank pin 51 approaches hook 54.l Actuator |06 engages and raises slider 88 upwardly a short distance sufficient to allow flexible contact arm 91 to engage contact post 95 just prior to the time Vthat crank pin 51 engages hook 54 to place the load of opening the valve against the 'action of coiled spring 45 upon the motor 10. During continuedyclockwise rotation of gear 55, the`valve Will be gradually' opened as heretofore explained and simultaneously the actuator |36 will continue to move slider 88 upwardly so that contact finger IOI will ride oil of cam surface |03 and engage resistance 84. When the valve has been completely opened, strip .89 will engage flexible contact arm' 93 to move the same from engagement with contact post 92.

Turning now to Fig. 2, a main control is herein illustrated in the form of a potentiometer room thermostat comprising a bimetallic actuating element I I0 which controls a movable contact member III that is adapted to sweep across a resistance ||2 upon changes in the temperaturev to which bimetallic element I I0 responds. The system further includes a pair of solenoid coils |I3 and I|4 which are connected in series and conjointly control the movements of a plunger II5. A switch assembly comprises a pivoted bracket IIE to which is secured a. pair of flexible contact carrying arms I I1 and ||8 that support contacts ||9 and |20. Plunger |I5 is connected to flexible arm II8 through connecting means including a shaft I2I and a light coiled spring |22.` On initial movement of plunger |I5 to the left, contact IIS is first moved into engagement with a relatively stationary contact |23 and upon continued movement of plunger I I5 to the left, contact I 20 is brought into engagement with a contact |24. Low voltage electrical power is supplied by the Hbwever, with An adjustable bracket |04 is provided with low` voltage secondary |25 of a step down transformer |26 having a high voltage primary |21 connected to line wires |28 and |25. The system also includes a pair of protective resistances |30 and 3| and preferably includes a limit control |32. Solenoid windings ||3 and .H4 are connected in series across the secondary |25 and through limit control |32 by means of Wires |33, |34, |35, |36, |31, 438 and |38.

Resistance 84 ls'connected in parallel with resistance II2 by wires l40, lili, |42 and |43 and these two resistances are likewise connected in parallel with solenoid windings |l3 and H4, in series, through protective resistances 30 and i3I by wires |44, |45, 45 and M1. The junction of solenoid windings l|3 and H4, movable contact member IlI, and contact nger lill are inter'- connectecl by wires |48, |40` and |50. Cam sui'- face |03 of bracket |02 isconnected to adjustable finger |05 of bracket |04 by a wire IBI. A small number of turns of solenoid I4 is connected to blades ||1 and |I8 by a wire |52. The remaining circuit connections will be pointed out in detail during the description of the operation of the system.

l Operation With the parts in the position shown, the temperature to which thermostat |I0 responds i's at or above the desired point as indicated by movable contact member III being in engagement with the extreme left hand end of resistance I I2. The valve is completely closed and contact finger |0I is out of engagement with resistance 84 and riding on cam surface |03. Finger- |05 has been adjusted so that it engages substantially the midportion of resistance 84. It will be noted that solenoid coil l| I4 is substantially sliort-circuited by wire |36, wire- |41, protective resistance |30, wire |45, wire |43, movable contact member thermostatic element ||0, wire |49 and wire |48. If it were not for the protective resistance |30 the solenoid coil 4 would be completely short-circuited. The same would likewise be true of solenoid coil I|3 if contact finger |0| were in engagement with the lower end of resistance 84. However, contact finger IOI is engaged with the center rportion of resistances 84 through cam surface |03 of bracket |02, wire I5| and contact finger |05 of bracket |04. The current flow through solenoid coil'I I3 is therefore considerably larger than the current flow through solenoid coil ||4 and the plunger ||5 is in the extreme right hand position shown in the drawings wherein contacts I I9 and |20 are both disengaged from their cooperating contacts |23 and |24. Field windings 14 and 15 are therefore both deenergized, flexible contact arm 93 is engaged with contact post 92 and flexible contact arm 91 is disengaged from contact post 96.

Now if the temperature to which thermostatic element ||0 responds slowly begins to fall, movable contact member III will begin traveling along resistance I|2 toward the right hand end thereof and when movable contact member I I is contacting substantially the center portion of reristance I|2 the current flow through solenoids ||3 and II4 will become equalized. Plunger H5 therefore moves to its center position and contacts ||0 and |20 are thereupon brought into engagement with contacts |23 and |24, contact IIS first engaging contact |23 and contact |20 thereafter engaging contact |24. Engagement of contact |20 with contact |24 establishes an energizing circuit for field winding 14 as follows: secondary |25, wire |33, wire |53, wire |54, field winding il, wire lss, nexible cntact arm sa, contact post 92, wire |56, contact |24, contact I20,`

exible arm |I9, wire |52, a small number of turns of solenoid I|4, wire I36, wire |31, limit control |32, and wires |38 and |39 to the other side of secondary |25. Energization o f this angle field winding 14 suppliesenough power to rotor 69 to rotate gear 55 to begin to taire up the lost motion between crank pin 51 and hook 54, it being .v 54, actuator |06 engages slider 88 lifting it a small A'amount so that strip 89 moves away from flexible Acontact arm 91 and allows the latterto move into engagement with contact post 96. An energizing circuit for field winding 15 is thereupon established as. follows: secondary |25, wire |33, Wire llo `valve will continue to open and slider 88 will con- |53, wire |51, field winding 15, wire |58, contact.

post 96, vflexible contact arm 91, wire |59, contact |23, contact ||9, flexible blade ||1, wire |52, a

small number oi.' turns of solenoid coil H4, wire |36, wire-|31,"limit control |32, wire |38and wire |39 to secondary |25. This increased current iiow to solenoid winding II4 also helps to maintain contacts ||9 and |20 in firm engagement with contacts |23 and |24. The added power supplied to rotor 69 by ,energization of field winding 15A enables` motor 10 to `lift the valve `from its seat against the bias of spring 46 upon engagement of crank `pin 51 with hook 54. As the valve opens, slider 8,8 continues to move upwardly until contact nger rides off cam surface |03 and moves into engagement with resistance 84. The

tinue to move upwardly until such time as contact finger |0| engages resistance 84 at a point slightly above that which time thecurrent ows through solenoid coils I|3 and 4 will be so related that plunger will move slightly to the right to disengage contact |20 from contact |24. When this happens, field Winding 14 is deenergized. 'I'he valve now remains in the position to which it has been moved by the cooperation of iield windings14 and 15 since the power supplied by eld winding taken together with the friction throughout the mechanism is suiiicient to maintain the valve in such position but is insumcient to continue opening the valve'.

It will therefore be seen that with the valve in an initially closed position, the demand for heat must increase to such a point as` to require a substantial valve opening beforerthe valve will start to open. The minimum valve opening from a closed position, as will be seen from the foregoing description, is dependent upon the position of manually adjustable contact finger |05 along 'resistance 84. s

If the'temperature should continue to fall so that movable contact member I moves further along resistance ||2 toward the right hand end thereof, the current iiows through solenoid windings I3 and I4 will again be changed and plunger I I5 will again move to the left to bring contact I intoengagement with' contact |24. Field winding -14wil l thereupon be again energized to open the the'valve more widely and to additionally lift sliderV 88 which in turn moves Contact 7gg-finger `|0| upwardly along resistance v8.4.VK `When contact linger |9| has reached a point on'resistance 04 such that the current flows through solenoid windings |I3 and ||4 are again so related that plunger |I5 moves to the right and separates contact |26 from contact |24, the field winding 14 will again be deenergized and field winding 15 remaining energized will maintain the valve in its new position.

If. the temperature should now rise slightly, movable contact member III will move along resistance ||2 toward the left end thereof and the current flow through solenoid coil |I3 will be increased in respect to the current fiow through solenoid coil I |4. Plunger I|5 will therefore move slighty to the right to disengage contact I 9 from-contact .I 23. Both the field windings 14 and 15 are now deenergized and the'valve will begin to return towards closed position under the bias of spring 4,5 and at the same time slider 88 will move contact IOI downwardly along resistance 84. Such downward movement of contactIIll will change .the current flows through solenoid coils I3 and |I4'in suchmanner that plunger I5 again moves slowly tothe left, bringing contact I9 into engagement with contact |23 whereupon field,

winding 15 is again energized to prevent further with contacts |23 and' |24,l the strip 89 will move into engagement with flexible contact arm 93 to lift the same out of engagement with contact post 92 whereupon field winding-14 is deenergized and the valveis maintained in its full open position by field winding 15.` In this manner, the

maximum opening of the valve may be determined by adjusting the limit switch 92--93.

As the temperature rises, the valve will close more and more and contact finger |0I will move downwardly along resistance 84 until it passes' through the point at which contact finger |05 is in engagement with resistance 84 and until the demand for heat'is such that the valve reaches a position wherein contact finger |9| rides upon cam surface V|03 and moves out of engagement with resistance 84. At this time, finger |05 is electrically connected in the system again and direct electrical connection between `finger |0I and resistance 84 is discontinued. Inasmuch as movable contact member ||I is now contacting resistance ||2 at a point further towards vthe left end thereof than is necessary in order to bring contacts I |9 and |20 into engagement with con-l tacts |23 and |24, the' current-now through solenoid winding I3 will be increased in respect to the current flow through solenoid coil I I4 to such an extent that contacts I I9 and I 20 will disengage contacts |23 and |24 rendering both field windings 14 and 15 deenergized andthe valve will completely close. It will therefore be noted that when the valve approaches a predetermined minimum position after having once been opened, it will quickly and suddenly close. This minimum position during Y lclosing movement may be adjusted by moving cam surface |03 up or down.

From the foregoing description, it will be apparent that the present invention provides control mechanism whereby an clement 'or device to V be controlled remains in one position vuntil a' movable member has moved to a position correspond# n. un

at which time the valve moves quickly to such position. Thereafter, the valve opens more widely and/or moves to more nearly closed position strictly in accordance with demands until a minimum open position is reached at which time the electrical actuating means is deenergized and the valve quickly moves to fully closed position.

It will also be noted that only a single motive Imeans is utilized and that there are no latching mechanisms or other complicated mechanical features for locking the valve in its various positions. All of the functions are obtained by chang ing the energization of the single motive means.

The invention also provides an arrangement wherein a valve which is continuously biased to one oi its flow controlling positions is moved therefrom by the energization of all of the windings of a rotary electrical motor and is maintained in the new position to which it is moved by deenc-rgizing a portion of the held* windings but continuing energization of the remaining portion thereof.

If the supply of electrical power should fail at any time and itbe desired to open the valve, this may loe accomplished by manually depressing the outer end of lever l and pressing inwardly on pin 'i6 so that it extends under lever il and prevents its return to valve closed position. Such manipulationof pin l closes recycling switches il and 'i3 whereby upon the return of electrical power energizing circuits for both field windings lli and are immediately estabished to more widely open the valve thereby allowing pin l to return to its original position andv returning the valve to automatic control. This recycling circuit for held winding l is as follows: secondary |25, wire |33, wire |53, wire |54, eld winding "M, Wire 56B, recycling switch lll, wire lEl, Wire |62, and wire |39 to the other side of secondary |25. The

recycling energizing circuit for held winding 'l5 is as follows: secondary |25, wire |33, wire |53, wire i5?, field winding 15, wire |63, recycling switch '18, wire |64, wire |62, and Wire |39 to the other side oi secondary |25.

Where the valve of the present invention is utilized to control the now of `fuel to a burner, such as the ow of vgas to a gas burner, it is often necessary that a relatively large initial now be supplied in order to obtain proper igni-` tion and prevent pop-backs in the burner. This can be accomplished by adjusting contact finger E05 upwardly along resistance 84 so that the` initial opening of the valve will be suiciently wide to allow proper ignition. However, some burners require such an initial large opening of the valve that the modulating range of the valve upon a temperature fall is practically eliminated. In other words, with some burners, it is unsafe to open the valve initially except to a substantially completely full open position which means that the temperature or other condition must decrease or change to'such an extent that there is a substantially complete demand for heat before the valve may be opened. This allows only a very small further fall in temperature or change in the condition before the valve will be completely opened so that there is only a small range within which the valve may modulate in moving from closed to open position. In order to overcome this difficulty, it is desirable upon an initial call for a relatively small ow of gas initially to open the valve quite widely and then automatically return the valve to a more nearly closed position which corresponds to the demand for heat. rluis action is very simply accomplished by a small addition to the mech.d anism heretofore explained.

Referring to Fig. 3, an extra track or cani im has been provided. This traclr or cam oicourse should be secured to the panel oi Fig. l and overlies cam surface tail but engages the same. Now, upon an initial call for heat resulting in l movement of finger lili in an upward direction,

this finger will ride from cam surface upon cam surface il@ instead of riding ofi cam surface illtl and moving into engagement with resistance lift. The current flows through solenoid coils l itl and i lll therefore remain the same and finger lili continues its upward movement until it reaches a notch lli formed in cam surface lll@ whereupon contact inger moves into engagement' with resistance 3d. ri-"he cam surface lid may be adjusted so that its notch is opposite a point in resistance dit corresponding to any desired initial minimum opening of the valve. As shown, the notch lll is opposite a point near the upper end of resistance dit so the valve will open almost completely before finger iti passes through notch lll and moves into engagement with resistance At this time, the current flows through solenoid-coil llEl and lift will be instantly changed, the current ilow through solenoid coil iid being greatly increased in respect to the current i'low through solenoid coil llt. Plunger lid will therefore move to the righi-,sufnciently to disengage contacts il@ and l2@ from contacts i123 and 424 whereby held windings lt and le are both deenergizecl and the valve begins to close. is the valve moves toward closed position, contact linger it will move down resistance 8d until it reaches a position wherein the current `iiows through solenoid coils H3 and lle are so proportioned that contact HQ again engages contact |23 to energize eld winding 'l5 which, as heretofore explained, maintains the valve in whatever position it may have been upon such.

energization of eld winding l5. The valve is now free to modulate upwardly through a relatively large range of its movement during temperature fall. When the temperature rises to such a point that contact iinger lill moves downwardly into engagement with cam surface l 03, the valve will quickly close as heretofore explained and Contact finger IGI will ride under the cam surface il@ to the position shown in Fig. 3.

In this manner, if desired, the apparatus can be so arranged that the valve or other device vwill initially move through a large portion of its range and automatically move back to a position corresponding to the position of the control member which started the valve or device in operation. Thereafter the valve or device may modulate strictly in accordance with the demands until such time as it approaches its initial position whereupon it quickly moves to its initial position and remains therein 'until the cycle is repeated.

From the foregoing description, it will be seen that the present invention provides an extremely simple arrangement for controlling a valve or other device in the manners heretofore explained and that such control does not include any compllcated mechanical mechanisms. While a valve has been utilized in the description andthe drawings for explaining'the invention, it is to be understood that the valve could wellbe replaced by any other device or arrangement which it is desired to move or control in a similar manner. Furthermore, the movable contact member lll may respond to any temperature whatsoever or may respond to any other desired condition or be moved in any other desired manner. Various modications and changes can be made in the present invention by those skilled in the art and I therefore am only to be limited in accordance with the scope of the appended claims.

I claim fas my invention:

1. Mechanism of the class described, comprising, in combination, a movable member movable along a predetermined path of travel, electrical actuating means, a device controlled thereby, means associated with said electrical actuating means and movable member for controlling the electrical actuating means initially to energize the electrical actuating means to in turn move said device a relatively large amount only lupon relatively large travel of said movable member in one direction to a rst point, means associated with said electrical control means and movable memberr for thereafter moving said device back, and forth in small increments upon corresponding v movement of said movable member, and means associated with said electrical actuating means and movable member for quickly returning said device to its initial position upon travel of said movable member to a second point through which actuating means for thereafter increasing and decreasing said flow in small increments corresponding to continued and reverse movements of said movable member, and means associated with said movable member and electrical actuating means for discontinuing dow upon movement of said movable member in the reverse direction to a second point, said movable member moving through said rst point to reach said second point.

3. In combination, a. single valve biased to closed position, a member movable back and forth along a predetermined path of travel in response to changes in huid :dow demand, a single electric motor means for controlling the movements of said valve, and means associated with said movable member, valve and motor means for normally moving said valve in accordance with themovements of said movable member but operative to maintain said valve closed during movement of said movable member through aY predetermined portion of its range of movement, after which said valve is moved a relatively large amount to a position corresponding to the position of the movable member.

4. In combination, a single valve biased to.

closed position for controlling the supply of fuel to av burner, a member movable back and forth along a predetermined path of travel in response to changes in fuel flow demand, a single electric motor means for controlling the movements of said valve, and control means associated with said movable member and motor means vfor maintaining said valve closed until the movable mem- 5. In combination, a valve biasedt closed po- 20 sition for controlling the flow of fuel to a burner, a movable member movable back and forth along a predetermined path of travel in response to changes in fuel flow demand, a single electric motor means for operating said valve, means asso- 25 ciated with said motor means and movable member for maintaining said motor means deenergized until said movable member assumes a position `requiring a large enough supply of fuel for proper ignition whereupon said motor means is energized in such manner as to quickly move said valve to the required position and for thereafter controlling said motor means in accordance with the movements of .said movable member to move said valve in a plurality of relatively small increment's as the demand for fuel ow slowly changes.

6. In combination, a single valve for controlling the ow of fuel to a burner, a member movable in response to changes in fuel demand, electric motor means associated with said movable member and valve for controlling the movement rof the latter as the result of movements of the former, and means associated with said movable memben valve and lmotor means for initially opening said valve to a relatively large open position whereby to insure proper ignition and automatically returning the same to a position corresponding to the fuel ow demand upon initial movement of said movable member and for thereafter opening said valve in small increments upon continued movement of said movable member as the demand for fuel increases. g

'7. In combination, a valve for controlling the o`w of fuel to a burner, electric motor means in control of said valve, a member movable back and forth along a predetermined path of travel in response to changes in the demand for fuel, means associated with said movable member for controlling saidvmotor means initially to open the valve suiiiciently widely to supply a large enough fuel -iiow forY proper ignition and thereafter automatically to reduce the supply of fuel in conformity with the demand upon movement of said movable member to a position requiring a relatively small fuel flow and for subsequently operating said motor means to opensaid' valve further in a plurality of small increments as the demand for fuel increases. l i e 8. In combination, a vvalve for controlling the flow of fuel to a burner, a movable member movable along a predetermined path of travel in response to changes in the demand for fuel, electric motor means associated with said valve for moving the same in accordance with the movements of the movable member duri-ng predetermined movements thereof, and means associated with said valve and movable member for moving said valve to a relatively large open position and automatically returning the same to a position corresponding to the position of the movable member upon movement of the movable member to a rst point in valve opening direction and for closing said valve when said movable member reaches a second point during movement toward valve closing position, said second point not being beyond said first point in valve opening direction of movement of said movable member.

9. In combination, a fluid flow controlling element biased to one of its ow controlling positions, a rotary electrical motor including a pair of energizing windings, means for energizing both or" said windings to move said element to a new position against its bias and for deenergizing one of said windings when said element has been moved to its desired position, the other of said windings remaining energized to maintain said element in the position to which it has been moved against its bias.

l0. in a modulating control, in combination, an instrumentality movable through a given range and biased for movement to one of the limits of said range, a movable member movable throughout a predetermined range, an actuator for said instrumentality for moving the same to' varying positions against its bias and maintaining it therein comprising a single rotary electric motor rotatable in only one direction, and means for completely energizing said motor whenever said movable member moves to a new position during movement in 'one direction whereby the element responding to the position of the movable member.

ll. In combination, an instrumentality to be controlled movable throughout a given range and biased to move to one of the limits of said range, a

control member movable through a predetermined range of movement, a single rotary electric motor rotatable in only one direction, first and second switches, a circuit for partially energizing said motor to hold said instrumentality against' its bias in any position to which it is moved and controlled by the first switch, a circuit for completing the energization of said motor when the second switch is closed whereby the instrumentality may be moved to a new position against its bias, means associated with said movable member for closing both of said switches, and means controlled by movement of said instrumentality for opening said second switch when the instrumentality has been moved to the desired position.

, 12. In combination, an instrumentality to be controlled movable throughout a given range and biased to move to one of the limits of said range, a control member movable through a predetermined range of movement, a single rotary electric motor rotatable in only one direction, iirst and second switches, a' circuit for partially energizing said motor to hold said instrumentality against its bias in any position to which it is moved and controlled by the iirst switch, a circuit for completing 'the means conjointly controlled by said movable meinber and said instrumentality for closing said second switch when the instrumentality is in a position corresponding to the position of said movable member, for closing both of said switches when the position of'said movable member requires further movement of the instrumentality against its bias and for opening both otsaid switches when the position of said movable member requires movement of said instrumentality by its bias.

i3. In combination, a member to be controlled and biased to a predetermined position, a rotary electrical motor rotatable in only one direction for moving said member against its bias and includinga plurality of windings, switching means selectively operable to energize two of said windings to produce a magnetic ux sufcient to move said member against its bias, to energize one of said windings to produce a magnetic flux suficient to maintain said member in a position other than its biased position or to control said windings to produce a magnetic ilux suihciently small to allow said member to move towards its biased position, and means for controlling said switching means.

le. in combination, a member to be controlled and biased to a predetermined position, a rotary electrical motor rotatable in only one direction for moving said member against its bias and including a plurality of windings, switching'means selectively operable to energi'ze said windings to produce a magnetic flux suiicient to move said member against its bias, to energize only one or said windings to produce a magnetic flux only 22 suiicient to maintain said member in a position other than its biased position or to control said windings to allow said member to move towards its biased position, a member movable throughout a predetermined range of movement, and

means conjointly controlled by the movements of said rst-named member and said movable member for controlling said switching means.

l5. En combination, a valve biased to closed position in control of the supply of fuel to a burner, a single electric motor rotatable in a single direction for moving said valve toward open position against its bias, means connecting said motor and valve, switching means selectively operable to completely energize said motor to motor to allow the valve to move towards its n closed position under its bias, a member movable in response to changes in the demand for fuel, means conjointly controlled by said movable member and connecting means for controlling said switching means whereby the motor is normally selectively energized to position the valve in accordance with the position of said movable member, and means associated with said last-named means for operating said switching means to maintain the motor deenergized when the valve is closed until the movable member reaches a position such that the valve will initially open sufficiently to supply enough fuel for proper ignition. f f

16. In combination, a valve biased to closed position, in control of the supply of fuel to a burner, a single electric motor rotatable in a single direction for moving said valve towards open position against its bias, means connecting said motor and valve, switching means selectively operable (ffl to completely energize said motor to move the valve towards open position against its bias, to

partially energize said motor to hold the` valve in any of'its open positions against the bias of the valve or to operatively deenergize the motor to allow the valve to move towards its closed position under its bias, a member movable inresponseto changes in thedemand for fuel, means conjointly controlled Vvbysaid movable member and connecting means for controlling said switching means whereby the motor is normally selectively energized to position the valve in. accordance with the position of said movable member, and means associated with said last-named means'for operating said switching means to maintain the motor ccmpletely energized upon complete energization thereof when the valve is in closed position until the valve is opened to a position supplying a suiicient ilow of fuel for proper ignition and then returning the switching means to the conjoint control of the movable member and connecting means.

'17. In a heating system, incombination, a

single'valve in control of the supply of fuel to a 'bui-ner, a movable member responsive to the temperature of the space to be heated, and control meansassociated with said valve and movable member for initially opening said valve relatively widely to insure proper ignition at'the burner upon a rst fall in temperature, automatically lreturning the valve to a position corresponding to the temperature of the space, and thereafter moving the valve toward wide open position in a plurality of steps as the space temperature continues to fall.

l 18. In combination, a device to be controlled, a member movable back and forth along a predetermined path of travel. electric motor means associated with said movable member and device for controlling the movement of the latter as the result of movement of the former, and means associated with the movable member, device, and motor means for init-'ally moving said device upon initial movement of the movable member in one direction an amount which is larger than the movement which would correspond to such initial movement of the movable member and automatically returning the same to the position corresponding to the position of the movable member, and for thereafter moving the device in the same direction in small increments as the movable member continues to move in said first direction.

19. In combination, a device to be controlled which is biased to move to an extreme position,

a single rotary electrical motor associated withv said device for moving the same to a position other than its biased position and includling a plurality of windings, a controller forenergizing the windings suilicientiy to cause the motor to move the device to a new positionagainst its bias, and switching means controlled by movement of .said device for energizing only part of said wind- 'ings of the motor to cause the same to maintain 1 the device in the position to which it had .been

moved when the energization ofthe motor windings was changed.

20. In combination, a device to be controlled biased to an extreme position, a-rotary electrical motorincluding a pair of energizing windings, a controller for energizing both` of said windings to move the device to a-new, position againstits bias, and switchingmeans. for operatively deenergizing one of said windings when the'device has been moved to its desired position, the other of said windings remaining energized to maintain the device in the position to -which it was formerly moved by the energization of both of said windings.

v21. In combination, a device to be controlled the device against its bias', said changed energizetion of the motor windings being sucient to maintain the device in its new position.

22. In combination, a device to be controlled y and biased to an extreme position, a single rotary electrical motor for moving said device to a newA position against its bias, connections between said motor and device including a lost-motion connection, a controller, circuit connectionsv controlled by said controller operative partially to energize the motor whereupon the motor takes up said lost-motion connection, switching means operated by the motor while taking up the lostmotion connection for completely energizing the motor whereby the same is energized suiiciently -to move the device against its bias after all the lost-motion is taken up, and switching means operated when the device has been moved to a desired position to reduce the motor energization to maintain the device in such new position.

23. In combination, a device to be controlled and biased to an extreme position, a single rotary electrical motor for moving said device to a new position against its bias and including a pair of energizing windings, connections between said motor and device including a lost-motion connection, a controller, circuit connections controlled by said controller operative to energize one of the motor windings whereupon the motor takes up said lost-motion connection, switching means operated by the motor while taking up the lost motion connection for energizing the other of the motor windings whereby the same is energized sufficiently to move the device against its bias afterall the lost-motion is taken up, and switching'means operated when the device has been moved to a desired position to deenergize one of the motor windings to maintain the device in such new position.

24. In combination, an instrumentality to be position, partially energizes the motor to maintain the instrumentality in any of its positions against its bias when the switching mechanism is in its second position,` and operatively deenergizes the motor when the switching mechanism is in its third position whereby the instrumentality is free to move under its bias, a controller, and connections between said controller and motor for conjointly controlling said switching mechanism. Y. y

In combination, an instrumentality to be controlled movablethroughout a given range and biased to one of the limits of said range, a single rotary electrical `motor rotatable in only one direction and arranged to move said instrumentality against its bias, three-position switching mechanism, circuit connections by which the switching mechanism completely energizes the motor to move said instrumentality against its bias when the switching mechanism is in its iirst position, partially energizes the motor to maintain the instrumentality in any of its positions against its bias when the switching mechanism is in its second position, and operatively deenergizes the motor when the switching mechanism is in its third position whereby the instrumentality is free to move under its bias, electrical means in control of said switching mechanism, a controller, and connections between said electrical means, controller, and motor by which the energization of the `motor is conjointly controlled by the controller and motor.

26. In combination, an instrumentality to be controlled movable throughout a given range and baised to one of the limits of said range, a single rotary electrical motor rotatable in only one direction and arranged to move said instrumentality against its bias, three-position switching means, circuit connections by which the switching mechanism completely energizes the motor to move said instrumentality against its bias when the switching mechanism is in its iirst position, partially energizes the motor to maintain the instrumentality in any of its positions against its bias when the switching mechanism is in its secondposition, and operatively deenergizes the motor when the switching mechanism is in its third position whereby the instrumentality is free to move under its bias, electrical means in control of said switching mechanism, a currentvarying controller, a current varying device operated by the motor, and connections between the current varying controller, current varying device, and electrical means.

27. In combination, an instrumentality to be controlled movable throughout a given range and biased to one of the limitsof said range, a single rotary electrical motor rotatable in only one direction and arranged to move said instrumentality against its bias, three-position switching means, circuit connections by which the switching mechanism completely energizes the motor to move said instrumentality'against its bias when the switching mechanism is in its iirst position, partially cnergizes the motor to maintain the instrumentality in any of its positions against its bias when the switching mechanism is in its second position, and operatively deenergizes the motor when the switching mechanism is in its third position whereby the instrumentality is free to move under its bias, a pair of oppositely acting electrical devices in control of the switching mechanism and arranged to cause the switching mechanism to assume its second position when both devices are equally energized and to assume its first and third positions when one or the other of said devices is energized to a higher degree, a variable resistance controller connectedvto said devices for varying the energizations thereof, and a variable resistance balancing means operated in accordance with the movements oi said instrumentality connected to said devices for rebalancing the energizations thereof.

28. In combination, an instrumentality to be controlled movable throughout a given range and biased-to one of the limits of said range, a single rotary electrical motor rotatable in only one direction and arranged to movesaid instrumentality against its bias, three-position switching means, circuit connections by which the switching mechanism 'completely energizes the motor to move said instrumentality against its bias when the switching mechanism is in its first position, partially energizes the motor to maintain the instrumentality in any of its positions against its bias when the switching mechanism is in its second position, and operatively deenergizes the motor when the switching mechanism is in its third position whereby the instrumentality is free to move under its bias, a pair of oppositely acting electrical devices in control of the switching mechanism and arranged to cause the switching mechanism to assume its second position when both devices are equally energized and to assume its iirst and third positions when one 'or the other of said devices is energized to a higher degree, a variable resistance controller connected to said devices for varying the energiaations thereof, a

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variable resistance balancing means operated in accordance with the movements of said instrumentality connected to said devices for rebalancing the energizations thereof, and means for short circuiting a portion of the variable resistance balancing means to prevent operation of the switching mechanism to its first position until the controller resistance is varied a predetermined amount from one of its extremes whereby to prevent an initial movementcoi the instrumentality until the controller requires a substantial movement thereof.

29. In combination, an instrumentality to be controlled movable throughout a given range and biased to one of the limits of said range, a single rotary electrical motor rotatable in only one direction and arranged to move said instrumentality against its bias, three-position switching means, circuit connections by which the switching mechanism completely energizes the motor to move said instrumentality against its bias when the switching mechanism is in its first position, partially energizes the motor to maintain the instrumentality in any of its positions against its bias when the switching mechanism is in its ysecond position, and operatively deenergizes the variable resistance controller connected to said ing the energizations thereof, and means for preventing variation of the variable resistance balancing means only during initial movement of Y the instrumentality from its extreme biased position.

I EWIS mL. CUNNINGHAM. 

